This invention relates to electromagnetic interference (EMI) shielding.
The prior art contains myriad designs of EMI shielding gaskets for doors or access panels of cabinets for housing electrical or electronic equipment. Some designs, such as a woven conductive sheath applied over a strip of pliable foam material, or a strip of rubber impregnated with particles of conductive metal, provide a good seal against electromagnetic emissions through the space between the door or panel and the rest of the cabinet, sometimes even when the door or access panel warps. However, they require the use of a latching mechanism therewith to attach the door or panel to the cabinet and to keep it closed. The trouble of latching and unlatching the latching mechanism encourages service personnel to simply remove the door or panel and keep the cabinet open, thereby defeating the purpose of EMI shielding.
Magnetic latches and gaskets, which rely upon magnetic attraction between a door or a panel and a cabinet, are also known. For example, U.S. Pat. No. 6,429,370 B1 discloses use of magnetic tape to form an EMI seal between a cabinet and a door and to adhere the door to the cabinet. The magnets are hard, that is, not compressible, physically. Therefore, a xe2x80x9cgasketxe2x80x9d consisting of a magnetic strip does not always provide a good seal between the door or panel and the cabinet, and may allow electromagnetic emissions to leak out if the panel or door warps.
This invention is directed to solving these and other problems and disadvantages of the prior art. Generally according to the invention, a pliable (e.g., compressible) gasket provides both the mechanical function of keeping a door or a panel mounted on (e.g., closed and tightly sealed against) a cabinet and the electromagnetic function of shielding against EMI emissions even if the door or panel becomes warped.
Specifically according to the invention, a gasket for preventing emissions of electromagnetic radiation from a cabinet having an opening and a panel for mounting over the opening comprises a first and a second half of the gasket, with the first half of the gasket comprising a first half of a self-engaging disengageable and reengageable fastener, such as a hook-and-loop fastener, for surrounding the opening, and with the second hag of the gasket comprising a second half of the fastener for engaging the first half of the fastener when the panel is mounted over the opening, and a material that blocks electromagnetic radiation carried by a pliable substrate for surrounding the opening and conforming to the shape of the space between the periphery and the panel when the panel is mounted over the opening.
This structure not only effectively seals the cabinet against emission of electromagnetic radiation from the cabinet, but also mounts the panel on the cabinet to keep the opening into the cabinet closed and tightly sealed, yet allows for easy removal and subsequent remounting of the panel.